Safety-fuse



A. L. EUSTICAE.

SAFETY FUSE.

APPLICATION FILED MAR-7,1918.

Patented D00.. 13, 1921.

UNITEDl STATES PATENT OFFICE.

SAFETY-FUSE.

Specification of Letters Patent.

' Patented Dec. 13, 1921.

Application led March 7, 1918. Serial No. 220,961.

To all whom it may concern Be it known that I, ALFRED L. EUs'rIoE, a Vcitizen vof the United States, and resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in VSafety-Fuses, of which the following is a specification.

This invention relates to inclosed fuses, or more strictly speaking to safety fuses.

One of the objects of this invention is to prevent reckless repair of safety fuses after the fusible element has melted, ortoprevent substitution of the fusible element.

Another object is to provide a simple and compact safety fuse of the non-renewable type adapted to meet the various requirements for successful commercial use.

Generally speaking these and other objects are accomplished by providing a safety fuse having in combination, a closed casing, a fusible element mounted therein and electrically connected rto parts exterior of the casing, and deiiecting means to prevent the introduction of a substitute for the fusible element. f

The invention is illustrated on the accompanying sheet of drawings, in which,

igure 1 is a longitudinal sectlonal view of a fuse embodying my invention;

Fig. 2 is a transverse sectional view taken in the plane of line 2-2 of Fig, 1;

Fig. 3 is a longitudinal sectional view of the same fuse taken at right angles to the section shown in Fig. 1; Y

Fig. 4 is a sectional view taken. in the plane of line 4 4 of Fig. 3;

Fig. 5 is a longitudinal sectional vlewof a fuse `embodying a modification of my 1nvention, and

Fig. 6 is a transverse sectional view taken in the plane of line 6-6 of Fig. 5.

The various novel features of my inventionv will be apparent from the following description and drawings and will be particularly pointed out in the appended claims.

As is well known, a fuse is placed in a circuit to protect that circuit and also to protect instruments or devices connected 1n the circuit. The fuse is designed to carry a certain load and when that load is exceeded, the fuse melts requiring a new fuse to be placed in the circuit. It is not u ncommon among some people to attempt to substitute for the fusible element by insertv vices connected therein.

ing another fuse of different capacity or even substitute a nail thereby defeating the very purpose of a safety fuse.

y means of my fuse construction, I prevent any unnoticed substitution of the fusible element, thereby requiring the use of a new fusevwhen the fusible element of the one in service has been melted.

To this end I have provided a fuse including a cylindrical non-conducting shell 10, the ends of which are covered by caps 11 of conducting material, the shell and caps forming a closed casing. Electrically connected to the caps 11 and extending through the shell 10 are spaced Yterminal straps 12 to which ends of the fusible elementl are connected by screws 14 or by any other suitable means. It is apparent that if the fuse thus far described is inserted between terminal clips so that thel metal caps 11 engage the terminal clips, the electric circuit will be completed between the clips by fusible element 13. If for any reason the circuit becomes overloaded a certain predetermined amount, the safety fusible element 13 will melt thereby protecting the circuit and de- It is under such conditions that attempts are made to substitute for the fusible element instead of using a new fuse. To prevent substitution of the fusible element 13, I have inclosed within the shell 10 at the ends thereof, or more strictly speaking intermediate the ends of the caps 11 and the terminal straps 12, deflecting means l5, which, as shown in Figs. 1 to 4, inclusive, are in the form of hardened steel disks. Preferably these steel disks are embedded in asbestos 16 or any other suitable insulating material which preferably is somewhat iiexible or will permit the disk to vary its normal position. By means of this arrangement it will be extremely diiiicult if not impossible for one to drive a nail longitudinally through the fuse structure to connect the terminal straps 12 or otherwise substitute for the fusible element originally in the fuse casing, and as a matter of fact if anyone should tamper with the fuse by attempting to substitute for the fusible element, the same would be observed readily, for the external parts of the fuse would be considerably damaged thereby giving notice that an attempt had been made to substitute for the original fusible element. In any event, it would be quite impossible to drive a nail through or around the deflecting disks 15 or to drill a hole therethrough in an effort to substitute. for the fusible element.v

Referring to Figs. 5 and 6 of the drawings,Y Y

casing, conducting caps Vinclosing the ends it Will be noted that instead ofusing a flat hardened steel disk 15, I have provided de! fleeting means in the form of semispherical' members 17 which are located intermediate the caps 18 and the terminal straps 19, said dellecting members preferably being packed in'asbestos or similar non-conducting material. i It is apparent that it Would be impossible'to drive al nail through this deflecting mea-ns or drill ahole in same for the purpose of substituting afusible element for the one originallyplaoed Within the casing.

By means ofthe arrangementlherein disclosed, a safety fuse of the non-reneivable type is provided Which is adapted to meet the various requirements for successful com` mercial use. l i A It is myuintention to cover modioations ofthe invention Which fall Within the spirit and scope of the following claims.`

I claim:

casing, and deflecting means 'contained with- 1n said casing and adapted to deiect any Vaxiallyentering element from axial penetration of the fuse.V

2. A safety fuse having in combination, af

closed casing, a fusible element therein electrically connected *to parts exterior Of the casing, and deflectingmeans yieldingly supportedwithin said casing and adapted to deflect any axially entering element from axial Vpenetration of the' fuse.

3. A safety fuse having in combination, ay v thereof, conducting members within the casing electrically connected to said'I caps', a fusible element connecting said conducting members, and deflecting means interposed between said caps and conducting members of the. easing; non-conducting materialfwithr in said casing, and deectingmeans embedin combination', aV l ded in said non-conducting material for pref venting the substitution ofthe fusible' ele-Vv ment. 1 Y

' Signed atChicago,Illinois,this 21st day of February, 1918. f Y ALFREDLL. EUsTroEf;

-lVitnesses: I Y i Y CEAS. L. BYRON, L.` E. HANNENL'" A i 

